Performance of an optical reader may be hindered where an optical reader is operated to read bar code symbols or other indicia of a substrate having a “shiny” surface. Such substrates can include, e.g., metal, glass, and laminated plastic. Light rays emanating from a reader that are projected on a highly reflective shiny surface of a substrate may be substantially entirely reflected directly onto a reader image sensor array. Artisans skilled in the art of optical readers regard a “specular reflection” read condition to have occurred where a substantial percentage of light rays are reflected from a substrate and directed onto a reader image sensor array. Light rays are said to be reflected at a “specular” angle when light rays are reflected from a substrate at about the angle of incidence. Specular reflection tends to saturate a reader image sensor array to cause decoding failures.
There is a need for an optical reader configured so that specular reflection read errors are reduced.